Retractable Y-shaped foils, adjustable in three dimensions

Inspired by the appendages of the America's Cup foiling monohulls, these Y-shaped foils have a wingspan of over 5 metres. They are designed to generate powerful lift, increase power and offer a wide range of adjustments to optimise flight at every point of sail and in all conditions. Beyond their impressive size, these foils feature many unique innovations.

Revolutionary U-shaped rudders

These are probably the most visually striking innovations on the new Maxi Edmond de Rothschild. To fly high above rough seas while maintaining control, the team wanted very long rudders that would remain in contact with the water. The challenge is that longer rudders tend to flex under load, severely affecting steering and the efficiency of their lifting surfaces. A new geometry was needed to give these appendages maximum stiffness, resist cavitation and ultimately improve control of the boat and make better use of its power. The result is a set of U-shaped rudders over 4 metres long, a metre longer than those on Gitana 17. Their shape, reminiscent of a tripod or an inverted π, is only the visible part of what makes them so distinctive.

A daggerboard optimised to stabilise the boat and limit cavitation

With its wide span, the daggerboard resembles an aircraft tail assembly, with two adjustable flaps: one on the vertical section and the other on the horizontal section, the distinctive “manta-ray wing”. On Gitana 18, the innovation is to position this wing behind the vertical part of the appendage, rather than directly beneath it, to minimise flow disturbance and cavitation.

Rig: adjustable spreaders to control mainsail power while sailing

Gitana 18’s mast is 1.50 metres taller than its predecessor’s. The boom is also shorter, creating a more slender sail plan. The major innovation is a set of spreaders that can be adjusted while sailing to bend the mast fore and aft. Actuated by hydraulic rams, these spreaders can pivot through 35 degrees to adjust the bend in the middle of the mast. This unprecedented system allows the sailor to control mainsail power: adding depth in light winds to take off sooner, or flattening the sail to reduce power at high speed or in strong winds. Adjusting the depth, and therefore the power, of the mainsail can also save a solo sailor time and energy by reducing the need for risky manoeuvres or headsail changes.

Central hull:
an integrated, structural coachroof

The naval architects and Gitana design team wanted an exceptionally stiff, structurally robust platform. This applies both to the floats, which must withstand heavy loads from the foils and rudders, and to the central hull, which is subject to torsion. The enclosed coachroof is integrated into the hull and contributes to its structural strength. Inside, the cockpit brings all sail-handling controls together, with ergonomics shaped by many hours of design and development. The coachroof also stands out for the number and size of its windows. This configuration meets the visibility requirements of the Ultim class rules and gives sailors the best possible view to keep a visual watch.

13.11.2013

Midway.

Overnight the two 70’ trimarans crossed the symbolic mark of 2,700 miles travelled, which is the equivalent of midway along the course. After a series of gybes to reposition themselves as they passed the Cape Verde archipelago, Edmond de Rothschild and her adversary are back on track heading southwards. This seventh day of racing is due to encompas…

par Gitana

Though the Doldrums are a zone that isn’t well liked by sailors, the same is also true for the onshore routers: “It’s always a complicated moment both on land and at sea. The forecasts aren’t good for this zone as they’re not reliable. As such we have to build up a picture of them based entirely on our observations of the satellite photos and other tools at our disposal. Jean-Yves (Bernot) is devoting all his time to this section at the moment, whilst I’m more focused on the boat’s ability to make headway and the positioning,” Antoine Koch explains, before going on to detail today’s timing: “The Doldrums appear to be very extensive and the boat should enter the thick of things by late afternoon today. The clouds will become part of the decor within the next 3 hours and will continue to build the further south they get. Jean-Yves and I will be on hand to adapt the course plan virtually in elapsed time.”

At the 0700 GMT ranking this Wednesday 13 November, the hierarchy remained unchanged! We can even note that the separation between Edmond de Rothschild and Oman Air – Musandam is completely stable. Indeed Sébastien Josse and Charles Caudrelier still had a slight cushion of a lead some 72.1 miles ahead of their pursuers compared with 72.7 miles at the same time yesterday. Positioned further over to the west than her adversary, the trimaran fitted out by Baron Benjamin de Rothschild boasted a lateral separation of around 90 miles in relation to the Omani one-design this morning.

Even though the ITCZ is not their favourite area, Sébastien Josse and Charles Caudrelier are very familiar with this zone having traversed it on a number of occasions. The undisputed leader since rounding Cape Finisterre some four days ago, the Gitana Team duo is tackling this ‘atmospheric’ crossing with confidence however. Indeed, in their current position, it will be down to Sidney Gavignet and Damian Foxall to take risks to get back into the match.

Ranking on Wednesday 13 November at 0700 GMT:

Edmond de Rothschild (Josse-Caudrelier) 2,608.6 miles to go /24.1kt average over 2 hours
Oman Air-Musandam (Gavignet-Foxall) 72.1 miles behind the leader /21.8kt average over 2 hours

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